Five-Lens Optical System with Aspheric Inflection Points for Low-Light Imaging
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Solution Overview
Problem
Conventional optical image capturing systems for portable electronic devices face challenges in capturing high-quality images in low-light environments due to limited light intake and difficulty in focusing both visible and infrared light simultaneously.
Innovation Solution
The optical image capturing system employs a five-piece optical lens configuration with aspheric surfaces and inflection points to adjust incident angles and modify optical paths, enhancing light intake and image quality, and is capable of dual-mode operation for visible and infrared light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional three or four lens optical system is used, then the device complexity is reduced, but the light intake is limited and imaging quality deteriorates in low-light environments
Solution Approach 1:
The optical system is divided into five separate lens elements (first lens L1, second lens L2, third lens L3, fourth lens L4, and fifth lens L5), each with specific refractive powers and surface configurations. This segmentation allows each lens to contribute differently to light gathering and image formation, thereby increasing overall light intake and imaging quality while managing system complexity through modular design
Solution Approach 2:
The five-piece lens configuration serves multiple functions simultaneously: the first lens (L1) with negative refractive power helps control aberrations and expand field of view, while lenses L2-L5 with positive refractive powers contribute to focusing and light gathering. The aspheric surfaces on multiple lenses (particularly L3, L4, and L5) provide both aberration correction and enhanced light collection efficiency, making each component multi-functional
2Illumination intensity
If the aperture is increased to capture more light in dark environments, then the light intake improves, but the manufacturing precision requirements increase due to the need for larger lens elements with precise optical properties
Solution Approach 1:
The patent employs aspheric surfaces on multiple lens elements (L3, L4, and L5 have aspheric object-side and/or image-side surfaces). These aspheric configurations allow for optimized light path control and aberration correction without requiring excessively large aperture diameters, thereby reducing the stringent manufacturing precision requirements that would otherwise be necessary for large-aperture spherical lenses
Solution Approach 2:
The system uses lenses with specific refractive index ranges (1.5 < Nd ≤ 1.7 for L1, 1.6 < Nd ≤ 1.8 for L2, 1.5 < Nd ≤ 1.7 for L3-L5) and controlled Abbe numbers (30 < NA ≤ 60 for L1, 20 < NA ≤ 40 for L2, 20 < NA ≤ 50 for L3-L5). These parameter specifications optimize the balance between light transmission, aberration control, and manufacturing feasibility, reducing the precision burden while maintaining high light intake capability
3Manufacturing precision
If the focal length is increased to improve image quality, then the imaging quality improves, but the device length increases which is not suitable for minimized electronic products
Solution Approach 1:
The five lens elements are arranged in a compact nested configuration where lenses L1-L5 are positioned close together along the optical axis with minimized spacing. The aspheric surfaces and specific refractive power distributions enable effective light focusing and aberration correction within a shortened optical path, achieving high imaging quality without proportionally increasing the overall system length
Solution Approach 2:
The patent utilizes the radial dimension through aspheric surface configurations on lenses L3, L4, and L5 to control off-axis light rays more effectively. This dimensional approach allows for improved image quality across the field of view without extending the axial length of the optical system, effectively trading radial surface complexity for axial compactness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively increases light intake and improves imaging quality, enabling high-quality image capture in low-light conditions while simultaneously focusing visible and infrared light, thus addressing the limitations of conventional systems.
Implementation Method 1
The optical image capturing system employs a five-piece optical lens configuration with aspheric surfaces and inflection points to adjust incident angles and modify optical paths
Data Source
AI summary
An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. At least one lens among the first to the fifth lenses has positive refractive force. The fifth lens can have negative refractive force, wherein both surfaces thereof are aspheric, and at least one surface thereof has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the fifth lenses. The optical image capturing system can increase aperture value and improve the imagining quality for use in compact cameras.